GUIDED BIKE RIDE, about three hours, led by a National Park Service ranger, with stops to view the Mall and discuss its history. Bring a bike and water; helmet required. 1 p.m., Thomas Jefferson Memorial, 900 Ohio Dr. SW. Free. 202-619-7222.

MAYAN MUSIC PERFORMANCE, guitarist Ranferi Aguilar performs traditional music on the guitar and other modern instruments. 5:30 p.m., National Museum of the American Indian, Welcome Plaza, Fourth and Independence SW. Free. 202-633-1000.

QUILTING DEMONSTRATION, by the Daughters of Dorcas and Sons. 1 p.m., Martin Luther King Jr. Memorial Library, Great Hall and second-floor east and west lobbies, 901 G St. NW. Free. 202-727-1291.

HARMAN THEATER OPEN HOUSE, ribbon-cutting ceremony for the new 775-seat facility, 11 a.m.; tours, demonstrations and performances by the CityDance Ensemble and Afro Bop Alliance, open rehearsals of the productions of "The Taming of the Shrew" and "Tamburlaine," children's activities, costume design talks, instruction on stage blood and stage combat techniques, and craft-making for children to create crowns to take home. 11 a.m.-7 p.m., Sidney Harman Hall, Shakespeare Theatre, 450 Seventh St. NW. Free. 202-547-1122 or http://www.shakespearetheatre.org.

KIDS ARCHITECTURE TOUR, for ages 6-12, learn basic architecture terms then join architect Mary Katherine Lanzillotta for a walk in the Blagden Alley and Shaw neighborhoods to see notable buildings, including the Blanche K. Bruce House (a national historic landmark on M Street), the Henrietta Apartment Building on N Street, a warehouse in Blagden Alley and Victorian and Italianate row houses; with light refreshments, sponsored by the Washington Architectural Foundation. 9:30 a.m.- noon. Free; reservations required by Sept. 13. Call Beth Judy, 202-667-5444, or send e-mail to bjudy@wafonline.org.

ARTS ON FOOT FESTIVAL, music, dance and theatrical performances, art displays by more than 70 artisans, culinary demonstrations, DC Shorts Film Festival at the E Street Cinema, children's programs, samples of food and wine from more than 30 area restaurants, tours of the new Sidney Harman Hall at the Shakespeare Theatre, and more. 11 a.m.-5 p.m., Canadian Embassy, Ford's and Woolly Mammoth theaters, Washington Stage Guild, National Portrait Gallery, National Building Museum, Goethe Institute, Old Post Office Pavilion, National Museum of Women in the Arts and other sites. Fourth and 14th streets NW, from L Street to Pennsylvania Avenue. 11 a.m.-5 p.m. Free. 202-482-7271 or http://www.artsonfoot.org.

"THE LURE OF SPICES," a museum staff member discusses spices that attracted Portuguese merchants to Africa, India and Asia and helps museum visitors weigh and grind spices before wrapping some in a fabric bag to take home. 2 p.m., Arthur M. Sackler Gallery, 1050 Independence Ave. SW. Free. 202-633-1000.